Accumulated Other Comprehensive (Loss) Income Attributable to Federated Investors, Inc. Shareholders (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013
Accumulated other comprehensive (loss) income, net of tax	$ (1,208)		$ (2,937)
Other comprehensive (loss) income, before reclassifications and tax	42		5,853
Other comprehensive (loss) income, before reclassifications, tax total	(29)		(2,454)
Reclassification adjustments, before tax	(225)		(4,648)
Reclassification adjustment, tax total	95		2,185
Net current-period other comprehensive income (loss)	(117)		936
Accumulated other comprehensive (loss) income, net of tax	(1,325)		(2,001)
Accumulated Net Loss from Designated or Qualifying Cash Flow Hedges [Member]
Accumulated other comprehensive (loss) income, net of tax	(3,185)	[1]	(7,071)	[1]
Other comprehensive (loss) income, before reclassifications and tax	(134)	[1]	(290)	[1]
Other comprehensive (loss) income, before reclassifications, tax total	49	[1]	105	[1]
Reclassification adjustments, before tax	4,015	[1]	4,949	[1]
Reclassification adjustment, tax total	(1,491)	[1]	(1,796)	[1]
Net current-period other comprehensive income (loss)	2,439	[1]	2,968	[1]
Accumulated other comprehensive (loss) income, net of tax	(746)	[1]	(4,103)	[1]
Accumulated Net Unrealized Investment Gain (Loss) [Member]
Accumulated other comprehensive (loss) income, net of tax	1,586	[2]	3,644	[2]
Other comprehensive (loss) income, before reclassifications and tax	744	[2]	6,308	[2]
Other comprehensive (loss) income, before reclassifications, tax total	(278)	[2]	(2,616)	[2]
Reclassification adjustments, before tax	(4,240)	[2]	(9,597)	[2]
Reclassification adjustment, tax total	1,586	[2]	3,981	[2]
Net current-period other comprehensive income (loss)	(2,188)	[2]	(1,924)	[2]
Accumulated other comprehensive (loss) income, net of tax	(602)	[2]	1,720	[2]
Accumulated Translation Adjustment [Member]
Accumulated other comprehensive (loss) income, net of tax	391		490
Other comprehensive (loss) income, before reclassifications and tax	(568)		(165)
Other comprehensive (loss) income, before reclassifications, tax total	200		57
Reclassification adjustments, before tax	0		0
Reclassification adjustment, tax total	0		0
Net current-period other comprehensive income (loss)	(368)		(108)
Accumulated other comprehensive (loss) income, net of tax	$ 23		$ 382

[1] Amounts reclassified from Accumulated other comprehensive loss, net of tax were recorded in Debt expense on the Consolidated Statements of Income.

[2] Amounts reclassified from Accumulated other comprehensive loss, net of tax were recorded in (Loss) gain on securities, net on the Consolidated Statements of Income.